Automatic telephone exchange



F'. A. LUNDQUIST ET AL r AUTOMATIC TELEPHONE EXCHANGE:

0riina 1F16d APr1 7. 1921 Patented July 28, 1925.

stars-s FRANK'A. LNDQST AND JOHN ii. nacre-or CHICAGO, ILLINors, assreivens, BY

wIESNE ASSGNMENS, T0 HENRY S. CISNE-AD, TRUSTEE.

AUTOMTIG TELEEB'NE EXCHANGE.

Application filed April 7, 1921, SerialNejllEE'OS. lRenewed December 15, 1924.

T0 all whom t may concern.'

Be it known that we, FRANK A. LUND- QUIsT and JOHN Aylaorr, citizens oitl the United States ot America, and residents ot Chicago, county ot Cook, and State ot illinois, have invented rcertain new and usetul Improvements 'in Automatic Telephone EX- changes, ot which the following is a specilication.

Our inven'tion'relates to automatic telephone eichanges, and more particularly to connectorl switches and the arrangements by which such switches are used in making telephonie connections to either private lines or party lines. The object ot the invention is to make improvements in the apparatus and circuits tor such connections.

The accompanying drawing is a' diagrr-,m in which the wipers are carried byA the well known longitudinal and rotary sha'tt. This sha'tt, and other pieces ot apparatus to be described, is moved by sylphons, which are lpneumatic motors ot the diaphragm type. Thesemotors are operated by compressed air flowing from a general supply pipe and are controlled by valves which are normally closed but which may be opened by pressing a projecting pin inward. The structure and function ot other devices will be s'et forth in -connection with the description ot'the operation.

The wires 2 and 3, extend` to a previous switch, Awhich may be ei'ther'aselect'cr or a line switch, and ythen to` a calling station where they1 are connected together ywhen the subscriber 'thereat removes his receiver from its hook. lVhen the connectors'hown in the drawing is seized, a current vliows;--bat tery X-l-Q-ca'llin'g station3-t'5-G-7 8-4-9-`1O-ground-'X. This attracts armature 11to open valve 12 and' permits valvel to close. Opening valve 12 permits compressedair to filow trom the supply pipe let to sylphon 15w'vhichjexpands to move 'lever 16 so asY to' open valve 1.7. (The supply pipe is marked' 14 at other places.) Between the valve 12 and sylphon 15' is a'che'clr'valvey 18 whichpermitsa quick flow of air to the sylphon 'but 'retards'. the exhaust therefrom. This maliessylphon 15 a slow motor which remains expanded during the brief closures of the valve112 hereinafter to be described. V

rthe opening 4ot' yvalve 1'?V permits nir to liow to valve 13-*whi'chwas previously closed,

nel to turn it oniits Land thru pipe 19 and check 19a to sylphon 20 which acts to turn lever 21 on its pivot' 22,. The tree yend oty lever 21 is connected thru linl'23 with the ta'ilvofla pawl 2% which ispivote'd to a 'slide 25. vYVhen the llever 21 is moved as previously described, the pawl is turned upon its pivotl until it engages a tiange ,on a channel l26,"al:`ter which the movement of the lever moves the slide until channel, and the short teeth on' the 'far side. When'the channel is rockedv on its pivots, .the teeth are alternately brought into and moved?V outI ot' the path ot the pawl carried in slide 25 and advanced by`lever 21. A spring 29 normally holds thechannel soV that the teeth on the far side areA in the path ot the pawl. A'sylphon 30 acts on the chanpivots against the action ot spring 29.

The operations describedup tov andincluding ven,g ;agernent between pavvl 24 and t0oth'27are automatic operationswhich occur as a result vof the switch being seized by the operation ot some otherV switch. lPart ot this operation is a short movement ot slide 25 which permits springs 31 and 32 to'open and remove ground connection trom wire The next thing` that occurs is an operation ot his dial by the calling subscriber,

which operation rapidly breaks and rem-altes the connection betweenf lines 2 and 3 a de- 's'irednumber of times. -Breaking the connection between these lines vbreaks the circuit 'tor vthe magnet l-, whereupon arma'- ture 11 falls backand permits valve 12 to close. But as the valve is quickly reopened by the remaking of the circuit, and as there is a check valve 18, such brief closing` or" valve 12 does not atleet sylphon 15 which continues to hold valve 17 -open so thev air supply pipe is extended to valve 13.

The vibration of the armature 11 which operates valve 12 without producing any result beyond that valve, opens and closes valve 13 rapidly a succession ottimes. Such opening or" valve 13 permits air `to iiow thru pipe Bil to an air distributor 35, and Ithru a branch `pipe 36 to sylphonBO to operate it.

In the pipe 36 is a check 37 which makes sylphon a slow motor which `remains ex- '4 panded during rapid vibrations of armature 11, but which contracts as soon as the vibrations cease. 30 turns the channel 26 so as to release pawl 24 :trom tooth 27 and permit slide 25 to ad-` of which is adapted to register with pipes entering the casing of distributor 35. The plunger 39 is connected to the slide 25 so that each movement of the slide causes a corre- Y sponding movement of the plunger. The movement of the slide which brought pawl 24 to tooth 38 also brought the lower end of the passageway 40 to the pipe 41 which leads to the sylphon 42. VThis sylphon operates the vertical movement of the shaft 43, and is the equivalent of the ordinary vertical magnet in this type of switch. The previously described air pulsations which enter pipe 34, by reason of valve 13 being opened by vibrations of armature 11, flow thru 40 and 41 to cause as many expansions and contractions of sylphon 42 as there are impulses ltlowing thru magnet 1 4. These operations of sylphon 42 cause corresponding upward steps of shaft 43.

On the termination ot the series of impulses just described, the circuit thru magnet 1-4 is closed and the armature 11 remains in attracted position. This cuts the air supply from sylphon 30 and pipe'34. VAs a consequence, the sylphon 30 contracts `and the channel 26 is turned on its pivots to release tooth 38 and permit sylphon 20 to advance slide 25 till pawl 24 engages tooth 44. This is a long step which bringsthe lower end of pasageway `40 to pipe 45 leading to therotary sylphon 46.

The next thing that happens is another operation of his dial bythe subscriber, which results as before in expanding the sylphoi 30 and in sending air pulsationsto sylphon V46 to turn shaft 43. The expansion of sylphon 30 releases tooth 44 and permits pawl 24 to advance to tooth 47. This is a short step which produced no result other than prepare the apparatus for the next operation. i

The rotary operation just described is the one which carries the wipers on shaft 43 to the terminals of the subscriber to be called, as is the ordinary practice. At the termination of this series of impulses, the sylphon 30 contracts as before, and the pawl24 advances a long step from tooth 47 to tooth 48. This long step carriesthe passageway 40 from pipe 45 so that no further impulses iowing thru pipe 34 will affect the position of the wipers.

This long step to tooth 48 also vbrings a This expansion of sylphon minals ot a busy line, then the spring 52 will s.

also furnish a ground `connection as tollows r--52--58-private wiper 54, and to ground on the busy called line in the ordi' nary manner.

busy line, then the private wiper indsno ground connection, and the movement of spring 6 from spring7 breaks the circuit for magnet 1-4. This opens valve 13 and permits air to flow to sylphon 30, which rocks 1 channel 26 and permits pawl 24 to advance from tooth 48 to tooth 55. This is a long step which follows immediately upon the heels of the previous long step from tooth 47. Previously, the long steps came as a result of attracting the armature 11, and the short steps as a result of releasing the armature. From this point on the order is re versed, andl long steps come as a result of releasing the armature and short steps `as a result of attracting` it. Y i

The long step to tooth 55 carries insulation 51 away from spring 6 so that it re-engages spring to remake thevcircuit for magnet 1-4 and cause the pawl 24 to advance a 'short step to tooth 56. These steps bring head 49 to the ringing position.

In the lower part of the drawing are shown three sets of bank wires representing three lines, any one of which may be called i by a subscriber ope-rating the 'connector But if the connector is moved to a nonshown. The central set contains three wires andrepresents a private line. The upper and lowersets each have a fourth.4 wire a permanent ground connection, and these sets I represent party lines. lt will be assumed that` the position to which the wipers move as Vpreviously .described is the private line. Y

',The wipers being on a private line, and

the head 49 being in a ringing position, the r circuit from the ringing generator includes contact makers 7-Wires-5S-springs 59 and GO-contacts 61,49-62-wires 63 and wipers 64 and (S5-bank wires 66 and 67- and called station thru the ordinary connections. There is a branch of this thru the relay 653-, but the armature of this relay is Y This'attracts the armature 72 and breaks.' the 'circuit for the magnet 1-4 at spring .10.

to tooth 73. This carries the head49 froml contacts 6162 to the talking posit-ion at contacts 74-.7 5. The movement of the head 49 from 61-62 breaks the circuit for relay 68-71, whereupon the circuit for magnet 1-4 is remade and the channel 26 moves back to its previous position. This permits the pawl to advance totooth 7 6,.but as this is a short step it affects nothing.L

The talking circuit Ican be readily traced from lines'2 and`3, thru condensers 50 and head 49 to the wipers 64 and 65 which were previously described as having come upon the terminals of the called subscriber. The called station gets its battery from X2 over connections which will be easily seen by examining the contacts on the head 49.

VIn the previousv description it was assumed that the calling subscriber had moved his wipers tothe terminals or a private line represent-edbythe bank wires 66 and 67. It will now -be assumed that he moves his wipers to the terminals of the upper party liner This brings his wiper 93 to the ter-- minal of the permanently grounded line 94 at the same time thatthe insulation 7-7 on slide 25 engages'a lever 78 pivoted at 79 and turns said lever to close two sets ot' springs. The closure of spring to spring' 81 connects ground thru 82 and 53 to the private wiper 54, and this is the saine whether the wipers be moved to a private or to a party line. Closing springs 86 and 87 when wiper 93 reaches the permanently grounded line 94 completes a circuitlas tollowsz-X-S3 coil 84-85+86-87--88-89;90*9192 93-94-ground-X- This attracts armature 95 to open valve 96 and permits air to expand sylphon 97, and this iii turn moves lever 9S on' its pivot to project the end 99 within af slot in the lower end of channel 26 and thereby lock it against movement.` This movement permits a breaking or the ringing circuit at the springs 59 and 60, and as this occurs'at the instant when the -head 49 reaches the ringing position, it will be e-vident that ringing does not occur at this point in making a party line connection as itv does Jwhen theV connection is to a private line.

At the time when the head 49 reaches the ringing position, the lower end of passageway 40 comes opposite the end of pipe 100. In the case of calling a private line, nothing happens as a result of this connection, but in calling some particular person on aparty line, the `calling subscriber must `operate his dial again to get the person desired.

This admits air to pipes 34 and 36. That going to sylphon 30 is without effect as the projection 99 locks channel 26 against movement, butA that going thru pipe 34 reaches pipe 100 and operates sylphon 101 to move ratchet wheel 102, and sylphon 103A to close springs 104 and 105. The sylphon 101. responds by as 4many expansions and contractions as there are impulses sent to magnet 1-4 `by the dial operation, vbut the sylphon 103 remains expanded during pulsations because of afcheck valve v106 which makes 103 into a slow motor. The move ment of the ratchet wheel 102 opens the connection between springs 90 and91, but the sylphon 103 bridges the connection between 88 and 92 by way of springs 104 and 105 so that t-hevcircuit 'of magnet 84 remains un` affected. j j

The contact makers 57 are insulatingly carried on the shaft ofratchet 102 in" the same way that wipers arel carried onthe ratchet shaft 43. W'hen the ratchet wheel 102 is advanced, the contact makers 57 are moved from the regular ringing connection at 107 lto one or anotherl of the adjacent variable ringing connections, upon how ma-nyimpulses are sent to the magnet 1% by the dial operation.

When theI dial operation ceases, armature" 11 remains attracted yto close valve 13 and cut the air supply from pipe 100. Theconsequent contraction of sylphon 103`breaks the circuit for magnet 84 and this in turn cuts the air supply from sylphon 97. This lets lever 98'fall back to release channelf26 and to close springs 59 and 60 to their adjacentl contacts. This re-establishes ringing connection thru head 49 to the party line, the particular signal sent to the line being determined by the position lof the contact makers "57. From this point on the operation is the same as in private line. Y f

lVhat we claim is l 1, In a telephone switching mechanism, a slide and means for placing under a strain to move it, an escapement and control therefor for permitting such movement, a plurality of motors, a source of air pressure for operating saidrmotors, and an air distributor operated by said slide and arranged to permit air to flow from the sourcev to -the motors in succession.

2. lin a telephone switching mechanism,-

a slide and means for moving it, devices for controlling` such movement, motors for moving the switching mechanism, a source of air pressure, and an air distributor moved by the slide to admit air to said motors in succession to cause the operation thereof.vv

depending the case of calling a CII iso

Contact vmakers thru which r` desired` ringing connections are madeto said `vvi5pers,-pneu=l` matic motors for `moving the `Wipers-in? a' primary and secondary movement, a ypneumatic motor' for moving the contact inakers;1

a source' of air pressure, and means-torconnecting saidmotors m successionl to saidA f i locking-said controlling :device fand breaking =1 source. y l y L 5. In 'a switching mechanismuarrangedtof make connections to either private kor partyl lines, motors for i moving thef mechanism,A aprogressively `movable controlling: devicey for controllingr said motors successively, means for continuing the movement of saidf device after the last `motor has l operated, and a locking `device controlled over avviper of saidswitching mechanism for holding the controlling deviceonly When the mechanism engages a partyilin'e.

6.` The combination With `a switching mechanism,ga plurality lof partylines, pneu` matic devices for `moving ythe mehanism to engagement Wlithone of said lines,l andV variable ringing connections, Aof means by which the Vmoved `parts jarc isolated` trom ringing connections when oneof said lines is engaged,.contact makers, pneumaticde-` vices for movingthemto engagement with a .desired one of the ringing connections, and'automatic meansffor extending the ringn ingconnection to movedparits ofl the mech anisni when the 'desired connection is made by the contact makersA l 7;! A source' of ringingcur-rent, a ringing connection having on oneend mov-able contact makers normally connected .to said source and having on the other end stationary terminals, a. contact head movable to engagement With said terminals, and means operated during such movementof said head for breaking the ringing connection.

8. A source ofV ringing current, a ringing4 connectionhaving on one end contact makersl normally connected to said source and having on the other end stationary terminals, ai movable part serving to connect a telephone line to said terminals, `means associated with such movement of said part for breaking the rin-ging connection, other sources of ringingicurrent,means formoving said contact makers to anyone ofthe other of said sources, and means by which upon said contactimakers coming to rest uponl any one of the other of said sources the previously broken ringing connection will be remade.`

S), A `series of sources of ringing current, Contact makers thru which any one of said sources may be connected to a .telephone line, a magnet serving to contro-l such connection, 4and a pair of springs for completinggan electrical circuit Jfor said magnet when said contact makers' `=are fin inormal position and; Jfor `opening sai'dtcircuitv as at resulty of said*- contact makers lbeing moved from` normal` position. A

lOnVipers, meansr for moving them step by step to autelephonic-connection, a `plu-` rality of sourcesv of electrical' energy, means for connectingwsaid sources successively tovsaid Wipers,=-a device Jfor controllingboth" said means, and. means-formsimultaneously;

the@ connection between .the Wipers and one i of said'sources.V i s 11. AV\,71pers,means-orfmovmg themlto aiV telephonie connection, aiplurality of sources of ringing current,` meansffor'connectingv said sources successively to connections -leadfl' ing `to said Wipers, means by which the lastV named connectionsy :are broken lduring the successive connecting operation, i and means 1 byyivhich the connection fromaifso-urce'to the Wipers r is automatically, re-establisl'ied` upon a l pause l occurring f in -ithe successive connecting operation.` Y y j 1 2. lVi'pers Ynfiovabl'e iby successive" steps toa desired telephonicconnection, a contact head movable by successive stepsto Adifferentv sources ot electricalenergy, iasub-cilivisio'nA oft one of said sources "into differentpartsj;

contact makersinovable to any ,tone oli 4said subdivisions, pneumatic motors for causingI all of saidmovementsra source-of air= pressure, anda magnet: serving in'succe'ssion to control the 4owof-airto and` fromvalloft said motors. i l y 13. In a` connector lsvvitoh,havingprimary and secondary 1 movementsy, primary f and secondary air` motors. for operating then switch, ancair pipeliaving outlets `to saidl motors, a source/ of -air pressure, means for` connecting gsaid'source toisaid pipe, andf a device in said pipe for successively ,opening said outlets to causesaidnmotors to operate insuccessionA y 14., In a connector switch having fprimary and secondary movements, primary v and secondary air motors t for operatingthe switch, an air pipe,.said motors having air` connections l-to said r pipe, means for delivering a series ofair pulses to said pipe, and. a devicein said pipe fortdeliveringthe first: of said series of air pulses :to the connection: leading `Vto the primarymotor and the second of saidhseries` of air pulses to the connection leadingrto the secondary motor to cause the/successive operation of said motors.

15. In a telephone system, connector switches Jfor establishingY connections with" single and party/lines,` pneumatic motors `for operating said' switches to establishfsucln connections, said single and party lines terminating indiscriminately ,with respectl toy each otherin the banks of saidsvvitches, a, plurality of sources of4 ringing current', contact 4makers `for selecting anyone of said sources of ringing current, said oomtacti makers normally in engagement with the operating said switches to establish suchV connections.

17. A series of sources of ringing current, contact makers through which any one ot said sources may be connected to a telephone line, a magnet servingA to control suchconnection, a pair of normally closed springs for completing an electrical circuit for said magnet when said contact makers are in normal position, said springs openedas a resultfof said Contact makers being moved from normal position, and a pair oitnorinally opened springs closed during the movement of said contact makers for maintaining said circuit for-said magnet uninterrupted during the movement'oi' said contact makers.

18. :inV afswitching mechanism arranged to make connections to either private or party lines, pneumatic motors for moving the mechanism to establish such connections, a controlling` device for controlling said motors, and a Vlocking device operated only when the mechanism engages a party line for locking said controlling device.

19. A source of ringing current, a. ringing connection having on one end movable contact makers normally connected to'jsaiid source and having on the other end stationary terminals, a contactfhead moved stepy by step 4by a pneumatic motorand an escapement to engagement with said terminals, and a pneumatic motor operated as a result otsuch movement of said head for breaking the ringing connection;

Q0. A source of ringing current, a ringing connection having on one end contact makers normally connected to said source and having on the other end stationary terminals, a movable part serving to connect a telephone. to said terminals, a pneumatic device associated with such movement ofsaid'part forvbreaking the ringing connection, other sourcesv of ringing current, a pneumatle motor forfmoving said contact makers to any one of the other of said sources, and means in response to saidv contact makers coming to rest upon any one of the other of said sources for remaking said previously broken ringing connection.

21. iVipers, pneumatic motors for moving loperable for 'selecting said wipers step by step to a telephone con-V nection, a plurality of sources of electrical energy, a pneumatic motor for connecting said sources successively to said wipers, an escapement and an air distributer for con-V trolling said pneumatic motorsl andmeans. for simultaneously locking said escapement and said air distributer and breaking the connection between .the wipers and one of said sources.

- 22. Vfipers, pneumatic motors for moving said wipers to a telephonie connection, a plurality of sources of ringing current,a pneumatic,motorV for connecting said sources successively to connections leading to said wipers, means by which the last named connections are broken during the successive connecting operation, andymeans by which the connection from/one of said sources to the wipers is automatically re-established upon a pause occurring in the successive connecting operation. Q

23. 1n a connector switch having access to both party lines and single lines, a local switching device occupying different positions in succession ,during the operation of .said connector in selecting and establishing a talking connection with, a called line, means for automatically movingv said device to ringing position when-any line is connected with, a ringing' circuit automatically established in ringing position to signal the connected line it suchline is a single line, means forautomatically opening the ringing circuit if the connected line is a party line, anda ringingk current selecting device then the proper ringing current to signal the'desired station.

24. In ya telephone system, two classes of subscribers lines, private normal conductors associated with said lines, a connector switch having bank contacts in which the said conduct-ors terminate, a private wiper in said connector adapted. to engage only the said contacts associated withk the lines inA one class, another private wiper in said yconnector adapted to engage the said contacts associated with the li-nes of both classes, means for operating said connector to select a called line in either class, two kinds of ringing equipment associated with said connector," and means under control of the irst vprivate-wiperV for putting .one `or the other of said equipments in use-dependent on the class in which the called line belongs.

25. In a telephone system, two classes of subscribers lines, private normal conductors associated withsaid lines, aconnector switch having bank contacts in which said conductors terminate, a private wiper in said connector adapted to engage only the said con tactsassociated with the lines in` one class, another private` wiper: in saidconnector adapted to engage the saidA contacts associated with the, lines in vbothclasses, means for operating said 'connector to "select a called linein either class, means for signah ling the called line immediately if saidline belongs to one ot said classes, and ineans controlled over said first wiper to signal the called line only after an interval if said line belongs to the other of said classes.

26. In a telephone system, two classes of lines, twodigit telephone numbers assigned to the lines of one class, three digit numbers assigned to the lines in the other class, an automatic connector switchresponsive to thev calling ota two digit number, to call a subscriber on a line in the first class and re-v sponsive ltothe calling of a three digit number to calla subscriber on a line in the second class, and ringing equipment automatically started in each case when the calling number isfcompletedto signal the called subscriber.` n A i 27. In a telephone system, private` or individual lines and party lines, an automatic connector switch, means whereby a calling subscriber can operate'said connector in accordancewith desired telephone numbers to connect with desired ones of said lines, and ringing equipment automatically responsive after two digits have been called to signal thecalled subscriber in case such subscriber has afprivate line, and automatically responsive after three" digits have been called to signal the called subscriber in case such sub' scriber is on a party line. V

28. In a telephone system, a party line connector having primary.` andL secondary motors, an auxiliary ringing Current seleoting switch individual to said connector, `a:

pneumatic motor for operating said switch, a line relay in said connector, `and means for placing said motors under control of said line relay; V

29. In a telephone system, a party line connector 'having primary and secondary motors, an auxiliary ringing current selecting switch individual tosaid connector, a pneumatic motor for operating said switch,

n aline relay in saidconnector, and means for placing said motors successively under control of said line relay. l

80. In av telephone system, a combined individual and party line connector switch pneumatically operated to connect with individual and party lines, said switch having facilities for performing different characteristic ringing operations depending on the kind ot' line connected with, `and means in said switch automatically responsive when a line isconnectedwith for determining the character of the ensuing ringing operation. A i

31. In a telephone system, a combined individual and party line connector switch having two sets of test wipers, individual and `party lines 'accessible to said switch, private 'normal conductors for the party linesl terminating inthe bank accessible to only one of said i wipers, and individual and party lines private normal conductors terminating indiscriminately with respect to each otherin the bank accessible to the other of said wipers. A n

32; -In a telephone system, a combined in-` dividual and party line connector switch having four sets of wipers,individual and pary lines rterminating indiscriminately with respect toeachother in the banks and accessible to said switch through said wip-f ers, private and line normal conductors for the individual lines terminating in the banks accessible to only three of said wipers, and private and line normal conductors for the party linesterininating in the banks accessible to all of said wipers.

33. In a telephone system, va combined individual and party line connector switch having wipers, individual and party lines terminating indiscriminately with vvrespect to each other in the banks and accessible to saidV switch through said wipers, four sets of terminals for each line, ,two of said sets of terminals of each line used fortalking `purl poses, theother two :sets of `terminals of party lines used f Jfor testinglpurposes, and only oneof the'other of said two sets lof terminals ot theindividuallines used forV testing purposes, the last set of terminals ot'the individual linesbeing left dead.

Si. In a telephone system, connector switches for `establishing connections `with. single or `party lines, pneumatic motors for operating said switches to establish such connections, a plurality` of sources of ringing current, and means for selecting ar de-- sired one of said sourcesof ringing c'urrentl 35. In a telephone system,ra combined individual and party line connector switch for establishing connections with either individual `or party lines, and pneumatic `motors for operating said switches toestablish Vsuch` connections and signal any! desired party' on the line. f l 36,-` In "a telephone system, connector switches for `establishing connections with individual or party lines, said individual and partyl lines promiscuous'ly `interspersed with respect to each other fin thebanks of said switches, means whereby a calling subscriber can operate said switches in accordance withdesired telephone numbers to connect with desired onesot said lines, and ringing equipment automatically responsive after two digits have been called to signal the called subscriber in case such subscriberV has an individual line, and'jautomatically responsive "after three digits have been called to signal the called subscriber in case such subscriber is o n a party line.

37.` In a telephone system, connector switches for establishing connection `with V'individual' or party lines, said individual llO and party lines promiscuously interspersed with respect to each other in the banks of said switches, and means for operating said switches to complete connections with the terminals of called lines and applying ringing current thereto responsive to either two or three digits.l

38. In an automatic telephone exchange, wipers for making telephonie connections, contact makers through which any one of a plurality of ringing connections are made to said wipers, a pneumatic motor tor moving said wipers in a primary movement, a second pneumatic motor for moving said wipers in a secondary movement, athird pneumatic motor for moving said contact makers, a source of air pressure, and a distributor for connecting said motors in succession to said source.

39. In a telephone system, a pneumatically operated connector switch for completing connection with the terminals of a called line and applying ringing current thereto responsive to either two or three digits.

40. In a telephone system, subscribers lines divided into two classes, a connector switch having wipers for completing a telephonie connection to said lines, a pneumatic motor operated in response to the first set oit impulses transmitted to said connector for moving said wipers in a primary movement, a second pneumatic motor operated in response to the second set of impulses transmitted to said connector for moving said wipers in a secondary movement into engagement with the bank terminals of the called subscribers line corresponding to sai/ l sets of impulses, ringing current, means for applying ringing current to said called line aiter said two sets of impulses have been transmitted if said line is in the first class, and means for preventing the application of ringing current to said line until a third set of impulses have been transmitted to said connector if said line is in the second class.

41. In a telephone system, a connector switch adapted to be pneumatically operated to establish connections with individual or party lines, said linesdivided into groups, said individual and party lines promiscuously interspersed with respect to each other in the vbank of said switch, means for operating said switch vertically to select a group of lines, means for rotating said switch to select a line in the selected group, a plurality of sources of ringing current, and means for selecting a desired one of said sources of ringing current.

4:2. In a telephone system, a connector switch for establishing connections with individual or party lines, said individual and party lines promiscuously interspersed with respect to each other in the bank of said switch, a plurality o't sources of ringing current, a pneumatic motor in said switch, and means for operating said motor for selecting a desired one of said sources ot ringing current.

43. In a telephone system, a connector switch adapted to be operated by pneumatic motors to establish connections with individual or party lines, said individual and partly lines proiniscuously interspersed with respect to each other in the bank of said switch, said switch having facilities for performing different characteristic ringing operations depending on the kind of line lconnected with, and means in said switch automatically responsive when a line is connected with for determining the character of the ensuing ringing operation.

FRANK A. LUNDQUIST. JOHN A. KROPP. 

